Correct washing of the wells is very important for a successful ELISA. Deionized or distilled water should be used when diluting the concentrated Wash Buffer.
There are some tips for correct washing in ELISA operation:
Using multi-channel pipette
Firstly, check the strips in the plate to make sure they are firmly in the plate holder. Secondly, empty the liquid in the plate by decanting. Fill each well with Wash Buffer of the volume specified in the manual. Set a timer for the recommended time and let the Wash Buffer soak in the wells. Decant the wells by inverting the plate and rapping it against clean paper toweling. Repeat this procedure as suggested in the manual. After the last decanting, remove any remaining Wash Buffer by inverting the plate and blotting it dry by rapping it firmly against clean paper toweling on a hard surface. Do not let the wells standing to dry. Proceed immediately to the next step in the manual.
Using manifold dispenser or autowasher
Equip the dispenser or autowasher with an appropriate vacuum supply (refer to manufacturer’s guidelines). Ensure that each cannulae is dispensing and aspirating properly. Set the volume of Wash Buffer in each well and soaking time for each washing. Then put the plate in. Ensure that no Wash Buffer is left in the wells after aspiration.
Washing the plate too rapidly or too slowly, incomplete washing or aspirating, and letting the wells standing to dry are factors that will affect the precision of the ELISA.